HP XC System Software Administration Guide Version 3.2

Use the following procedure to install software RAID on client nodes:
1. Log in as superuser (root) on the head node.
2. Generate a list of nodes on whose disks you will install the HP XC System Software with
software RAID.
3. Edit the /etc/systemimager/systemimager.conf file as follows to specify a list of
nodes that will use software RAID:
• Add or change the following entry in this file to specify software RAID-0 for the list of
nodes:
SOFTWARE_RAID0_NODES = list of nodes
For example, use SOFTWARE_RAID0 = n[1–5,9] for nodes n1, n2, n3, n4, n5, and
n9.
• Add or change the following entry in this file to specify software RAID-1 for the list of
nodes:
SOFTWARE_RAID1_NODES = list of nodes
For example, use SOFTWARE_RAID1 = n[1–5,9] for nodes n1, n2, n3, n4, n5, and
n9.
4. Ensure that no jobs are currently running on the HP XC system.
5. Run the cluster_config command to update the system configuration database and
update the golden system image:
# /opt/hptc/config/sbin/cluster_config
6. Reimage the nodes. See Chapter 11 (page 139) for specific information.
7. Use the following command on the imaged node to verify the software RAID installation:
# cat /proc/mdstat
The cat /proc/mdstat command is discussed in “Examining a Software RAID Array.”
19.4 Examining a Software RAID Array
You can examine the RAID array with either of two methods.
One method is to use the following command to return data from the system's process information
pseudo–file system:
# cat /proc/mdstat
Another method is to use the mdadm command, which is a utility for creating, managing, and
monitoring devices using the multiple devices driver. The following command line entries are
examples of the use of the mdadm command; the example uses a Serial ATA (SATA) disk.
# mdadm --query /dev/sdb1
/dev/sdb1: device 1 in 2 device active raid1 md1.
Use mdadm --examine for more detail.
# mdadm --detail /dev/md1
/dev/md1:
Version : 00.90.01
Creation Time : date and time
Raid Level : raid1
Array Size : 292608 (285.75 MiB 299.63 MB)
Device Size : 292608 (285.75 MiB 299.63 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : date and time
State : clean
228 Managing Software RAID Arrays